Air bag foe



-J. F. PALMER AU? BAG FOB USE IN THE MANUFACTURE OF PNEUMATIG TIRESFiled March 6.

Feb. 19, 1924;

Vll

Weigel-ea i9, 1924.

UNITED STATES PATENT oFFicE.

JOHN FULLERTON PALMER, OF ST. JOSEPH, MICHIGAN.

AIR BAG FOR USE IN THE MANUFACTURE 0F PNUMATIC TIRES.

Application filed March 6, 1920.

T 0 all whom, it may concern:

Be it known that l, J oHN FULLenToN Piar-ian, a citizen of the UnitedStates, residing at St. Joseph, in the county of 'Ber- 'rien and Stateof Michigan, have invented certain new and useful Im rovements in AirBags for Use in the B anufacture of Pneumatic Tires, of which thefollowing is a specification.

Thisinvention relates to improvements in apparatus or appliances for themanufacture of pneumatic tires of the type known as doiible tube tires.It is well known in tires of this ltype the casing or outer part theieofis separate from the inni-i tube and is U- shaped in cross-section, theedges of this outer casing being adapted to engage with oiminga wheelriin. Stated more particularly; the invention relates to apparatus forsecuring better results in the vulcanizing of outereasings of the typereferred to.

It isi-common practice in the manufacture .ofl'tiifess especially cordtires, to expand the tirein the process of final vulcaniza-tion, to apredetermined degree, usually by what is termed an air bag, the latterconstituting a smooth surfaced,- 'flexible, expansible and symmetricalagent for the urpose, the use of which tends to expand t e tiresymmeti-icallyv as a whole though not rigidly so. These air bags, as nowcommonly constructed and empio ed, are to a certain degreeobjectionable, in that they do not expand equally in all directions, butare limited in theiraction by the assembl of the cords or yarn going tomake up the abrio which constitutes the strain-resisting part of thetube oiair bag. It is the purpose of the present invention to rovide anair bag of the type described which will not only expand uniformlyin'all directions, but one which is also adapted to col-operate with thebeadfi'ming rings at the inner periphery'of the tire as aeompactingmember of the mold as- Sembly. To this end an air tube of rubber or thelike is provided, which's preferably surrounded with one or more liesor`=lay.

ersota knit fabric the chief c ariicteistic of which is its uniformexpansibility inia'll directions, and superimpose upon this fabricreinforcing layers of ordinar woven tire fabric bisc'ut to suitable with, frictioned and applied-to the-'inner periphery of the air bag; andextending up on either side a predetermined distance but not over theSerial N0. 363,909.

pable of expanding' both longitudinally and transversely at the sametime.

In order that the lower part of the air bag may constitute a. compactingmember in the mold assembly, the bag is made of a size so that the innerperiphery thereof, when in position Within a tire casing, projectsbeyond the inner periphery of said casing;r a suiiicient distance sothat the=inner periphery of the bag, or that ortion thereof which liesadjacent the beadorming flanges of the bend rings, will be free toexpand transversely and thus to press the edges of the casing' into firmengagement with said Ranges upon introduction of pressure into the bag.lt will be apparent, of course, that the brad-forming riiigs or otherparts of the mold assembly at the point Where the bag projects beyondthe inner periphery of the A' further object of my invention is topro lvide means whereby, after the tube or'air bag is once used, it maybereadily withdrawn from lthe finished casing and introduced into anunfinished one. In the present practice the bags become more or less setin their distended condition after they hare once been subjected topressure and the heet of vulcanization, and owing to this it .is ratherdiilicult to remove a bag from a finished casing without njur to theformer.` Furthermore, should the ag be removedv without injury, italmost invariably results, upon attempting to introduceitinto a new,unvulcanized casing, that the bag, owing to its enlarged condition,wrinkles or becomes otherwise distorted in the process. To obviate thisI provide in the tread ortion of the bag a knit fabric which rein orcessaid tread and which also permits o f the same being 'collapsedinto theinterior of the bag ipon the withdrawal of the air therefrom. Thisreduces the outer circumference of the bag to a (point where it is easytoremove the same an to later introduce it into a new, unvulcanized tirewithout distortion.

In the sectional View Adisclosed in the single ligure of the drawings,an enter casing is shown mounted on bead-forming rings and the air bagis shown in position Within the cas' In the drawings the bead-formingring is designated in its entirety as l0, and comprises t e usualcomplementa sections 10 and 10", designed to be secure together as at 10for the purpose of providing an annulus adapted to support the outercasing of the tire during the process of vulcansa tion. Around the outeredge of each of the sections 10* and lOlvthere is provided the usual.outstanding bead forming llanges 10d, designed to engage th sides ofthe casing adjacent its inner periphery and to form, with the aid of'the aibag, the beads on the inner edges of the casin to conform to theusual rimmed contour or the type of tire illustrated.

Mounted within the outer casing is the air bag 11, said ba beingprovided with the usual nipple 12 aving a passage extending therethroughfor the admission of fluid under pressure into the ba. when it isdesired to expand the same. onnected with the nipple at its outer endthere may be a pipe line 13 through which air or other fluid may beeither supplied to the bag or withdrawn therefrom after thevulcanization. A suitable valve 12 is provided in the passage of thenipple 12, so that the llow of fluid therethrough may be controlled.

According to the present invention, the air bag is comprised of a tubeof rubber surrounded by or having imbedded therein a strip or layer ofknit fabric llf, this fabric being so formed as to be expansible at thesame time both longitudina ly and transversely, so that upon theadmission of fluid under pressure into the bag a substantially uniformexpansio and ap lication of pressure to the outer c sing is o tained.Around the inner periphery?F of the air ba one or more layers or pliesjfwoven fabric 11h are provided, these elements providing a more rigidstructure where applied and extending up on either side of the ba apredetermine distance but terminating s ort of the outer periphery ortread surface thereof, as shown at 11 in the drawings. In this manner anair bag is provided the outer peri he of which 1s expansible and pliableor exib e to a rather marked ilegree, while the inner periphery thereofis of a stiier character, owing to the plies r layers ofreinforcingmaterial 11". Acc x ingly, after the rbag has 'neen inflated in order toexpand the casing 'during the process of vu canization, the outerperiphery ofthe b may be collapsed, as shown 1n dotted lines in thedrawings by merelywithdrawing the air from the bag and croatir r apartial vacuum therein. During this collli'psin'g of the bag along itsouter peri hery, however, the walls thereof, in whic is vulcanized thereinforcing layers, remain substantially in their normal, outwardlycurved positions, substantially as shown in the drawings. In this mannerthe outer circumference of the bag may be materially reduced to aid inremoving the same i and to also enable the sameto be readily and quicklyinserted in another unvulcanized casing.

As above outlined, it is preferred to construct bags .in accordance withthe' present improvements in suchwise that when placed within a casingthe inner periphery o f the bag will project. a certain degree beyondthe bead line or inner edges of the casing, in order that the air bagmay constitute a compacting member in the mold assembly. As nowconstructed, the inner peripheries ef bags of this character terminatein line with the inner periphery or bead line of the casing, orsubstantially so, so that upon the admission of fluid under pressureinto the bags the transverse expansion of the latter at the hase of thebead-formin flanges is materially retarded or limited, t iusrendering'the bags at this point ineffective to a ma rlred degree ascompacting members in the Lead-forming assembly. In the accompanyingdrawings the 'bag of the present im- 'irovements is shown, as aboveindicated, extending beyond the' inner periphery of the casing, thehead-forming rings being recessed as at l()c to receive the protrudingportion of the bag. By this construction an'd relative arrangement ofparts, when the bag is expanded, the'portions thereof in the vicinity ofthe bead-forming flanges will e1:-F pand in substantially the lsameproportion as the other arts of the bag and will serve to press the erges ofthe casing firmly against said flanges.

As the present improvements relate to the composition, construction andmounting of the air bag for use during the process of vulcanization inthe particular connection herein described, the mold usedin suchconnection has not been illustrated. Its use and relative arrangement,however, will be clearly understood by those skilled in the art.

From the above it will be observed that an air bag of the type describedhas been provided comprised` of rubber and fabric so assembled thatsubstantiall uniform expension is obtainable. It wil be further observedthat an air bag has been designed the outer periphery of which will,upon the creation o a partial vacuumwithin said bag, be collapsed whilethe inner periphery thereof, Acontaining' the reinforcing layers, willvremain substantially in its normal, out# the inner periphery of thecasing further ad vantnges are obtainable, ne compared with nir ba suchnow commonlyv en'iployed7 the chief advantage presented :y this. fen--ture residing in the freedom with which the inner periphery of the bagmay expand transversely in the vicinity of the beads so that the bag atthis point cooperates With the bend-'forming flanges in the nature of ncompeeting member and serves to firmly prem the inner edges, of thecasing against said flanges. Another important advantuge incidental tothe reeeesinuV of the bead-forniing rings for receiving t ie innerperiphery of the air bag is that; in this inzmner the bag, upon eachinfiation thereof, is mechanically and positivel i elined relative tothe easing and particu arly with respect to the sides thereof in thevicinity of the headed edges. This feature hai,- heen found in pmeticeto be advantageous und is not obtainable with air bags its nowconstructed and used.

It will be obvious to those eltilled in the nrt that various rhungee:intl inoditiratimis may be made in the present improvements Withoutdeparting from the Spirit of the in-y vention, sind accordingly it istnot desired to limit the saine except where limitations ap )ear in theappended claims.

claim:

1. In :in apparatus of the type described, an air bag' by mesme of whirhHuid preesure may be applied to the interior of a tire casing during theproeess of vulennizing, seid bag comprising a fabric Carens-S expanehlein all directions and reinforcing layers extending around the innerperiphery of seid bag and over a substantiel portion of the side wallsthereof? but terminating short of' ite` outer periphery whereby thelatter only will be collapsed upon the creation of n. partial vacuumWithin said beg.

2. A tubular nir bug of the t pe described eornprisud of rubber havingriin Jedded therein :i rai-mee of fabric expansihlo in all directions undai superimposed layer of reinforcing material applied to the innerperiphery of said beg.

ZS. A tubliiztr air beg of the type described having :l relatively thinouter peripheral portion expnneible Simultaneously in ltill di reotioneund relatively thick reinforced laterv:illy exl'ninsihle Side walls.

An expansible air lmpr ot the type dest'ribed comprised. of rubberhaving a layer of fabric expuneible in all directions imbedded thereinover the outer periphery thereof :ind relatively inexpnneible reinorcing materizd surrounding the inner periphery thereof.

`5. An air bag or" the type described Comprising :i tube of rubberhaving imbedded therein a ltnit fein-io expansible in all direotlons und:Superiinposed reinforoingtr strips applied to the inner periphery ofSuid bag :md terminating on either side thereof.

In testimony whereofpl have subscribed my name.

JUHN FULLERTON PALMER.

